The widely-used peripheral input device of a computer system comprises for example a mouse device, a keyboard device, a trackball device, or the like. With the progress of the times, a touch input device has been introduced into the market. By directly using the user's fingers or using a stylus to operate the touch input device, the computer system can be correspondingly controlled.
The applications of the touch input device are very extensive. In the early stage, a touch input device (i.e. also referred as a touchpad) is installed on a notebook computer. By operating the touch input device, the movement of a cursor may be controlled or a corresponding icon of a user interface may be clicked without the need of using a mouse to operate the notebook computer. In accordance with an advantage of the touchpad, the touchpad can be intuitively operated by the user and thus various commands can be correspondingly executed. With the advance of science and technology, a variety of touch input devices were developed. For example, a touch input device with a handwriting or drawing function (also referred as a handwriting tablet) has been introduced into the market. When the user writes characters or draws pictures on the handwriting tablet with the stylus or the finger, the corresponding characters or the corresponding pictures are shown on the computer system.
Generally, for facilitating carrying the touch input device, the touch input device is designed to have a small size while maintaining slimness and portability. However, the small-sized touch input device is not easily operated by the user. In addition, the manufacture has to impart more suitable functions to the touch input device.
Therefore, there is a need of providing an improved touch input device so as to overcome the drawbacks of the small-size touch input device.